a fortiori — a for·ti·o·ri /ˌā ˌfȯr shē ōr ˌī, ˌä ˌfȯr shē ōr ē, ˌfȯr tē / adv [New Latin, from the stronger (argument)]: all the more certainly: with greater reason: with still more convincing force used in drawing a conclusion that is thought to be even… … Law dictionary